<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<div id="app">
    <div v-bind:style="{ backgroundColor: backgroundColor, width: width + 'px' }"></div>
</div>
</body>
<script src="../../js/vue.js"></script>
<script>
    var vm = new Vue({
        el: '#app',
        data: {
            backgroundColor: 'red',
            width: 300
        }
    })
</script>
</html>
